Underreamer.



A. WILLARD.

UNDERREAMER.

APPLICATION FILED MAY s, 1903.

No. 762,458. PATENTED JUNE 14, 1904.

no MODEL.

UNITED STATES Patented. June 14, 1904.

PATENT OFFICE.

UNDERREAMER.

SPECIFICATION forming part of Letters Patent No. 762,458, dated June14;, i904,

Application filed May 5, 1903. Serial No. 155,719. (No model.)

T0 at whom it may concern:

Be it known that I, ARTHUR WILLARD, a citizen of the United'States ofAmerica, residing at Los Angeles, in the county of Los Angeles and Stateof California, have invented a new and useful Underreamer, of which'thefollowing is a specification.

My invention relates to underreamers for reaming out the holes of oiland Artesian wells, &'c., larger than the casing to permit theloweringof the casing.

The general object ofmy invention is to provide an underreamer ofexceedingly. simple, cheap, and durable construction which shall becomposed of few parts of such construction and interrelation as to avoidbecoming. displaced in the device and getting out of working order. 1

A further object of the invention is to provide an underreamer of theclass in which the reaming-bits are pivoted upon the mandrelbody properand are expanded by an automatically-operating wedge, the bits being sopivoted in the mandrel that the strain of under-reaming is substantiallytaken off the pivots and borne by the mandrel-body proper.

Other and further objects and ends in view will hereinafter appear fromthe detail description.

The invention consists in general and specific combinations of parts andconstructions, all as hereinafter described, and particularly pointedout in the claims, and will be more readily understood by reference tothe "accompanying drawings, forming a part of this specification, and inwhich Figure I is a longitudinal sectional view of an underreamerembodying my invention, the same being shown in connection with asection of a well-casing and in position for underreaming. Fig. II is apartial longitudinal sectional view showing the bits contracted forpassage through the well-casing. Fig. III is a partial side elevation ofthe mandrel, the reaming-bits being removed. Fig. IV is a bottom viewwith the reaming-bits in expanded position. Fig. V is a plan view takenon the line V V of Fig. II. Figs. VI and VII are side elevations of thereaming-bits which I employ. Fig. VIII is a bottom view of one of thereaming-bits As shown in the drawings, 2 represents the .mandrel, whichis provided with a central chamber 3, which extends longitudinallythereof, as shown. The lower end of the mandrel is shown best in Fig.III. This slotted portion is provided with inward projections 4 at theend of the mandrel, whereby abutments 5 are formed for the purposehereinafter set forth. The reaming-bits 6 are pivoted within the chamber7 thus formed above the abutments 5 by pins 8, which pass through eyesor holes in the bits and have bearings on the opposite walls of themandrel, as indicated by dotted lines inFig. III.

As shown in Figs. VI and VII the reamingbits are composed of the headportion 9, the

intermediate portion 10, and the blade portion 11. Theintermediate-portion is cut away to provide the shoulders 12, which, asshown best in Figs. I and II, have the two inclinations shown.

13 represents shoulders on the upper ends of the blade portions 11adapted to contact or abut against the ends 14: of the mandrel. Theinner sides ofthe bits are provided with sockets or Seats 15, adapted toreceive the spreader or wedge 16 when the bits are expanded, and thegrooves 17 in which the stem or rod 18 rests.

The stem or rod 18 is adapted to work in the chamber 3' and is providedwith a shoulder or flange 19, preferably formed integral therewith.

20 represents a barrel or cylinder about the rod 18 and extending up fora portion of the length thereof. This barrel or cylinder is providedwith a top plate 21 and a bottom plate 22. The top plate 21 may beformed integral with the barrel or loose or may be in the form of aloose collar or may be detachably secured on the top of the barrel, asdesired. The bottom plate 22 is preferably threaded onto the'bottom ofthe barrel. Above the barrel 20 a coiled spring 27 is interposed aboutthe rod 18 and bears against a head 23 on the rod. This head ispreferably in the form of a nut, engaging a thread on the end of therod, and by turnlng the nut down on the rod any desired tension of thespring can be secured. The wedge or spreader 16 is preferably formedintegral with the rod 18 and adapted when in the position of Fig. I torest on the seats of the bits.

The barrel 20 is provided with a longitudinal slot and the collar orflange 19 provided with a projection 2 k, extending through this slotand adapted to work therein. The mandrel 2 is provided with a way 25,which extends inward from the outer surface at an acute angle, as shown,and in this way is provided a pin 26, which bears against the projection2 1 and collar or flange 19 and extends when the underreamer is passingthrough the easing into contact with the inner surface of the casing,causing the rod 18 to be forced down, throwing the spreader or wedge 16out of the seats 15 of the bits, so that the bits drop of their ownweight into their contracted positions. The rod 26 thus forms automaticmeans whereby upon coming in contact with the casing the spreader orwedge is forced down against the tension of the spring 27. Toward theupper end of the pin 26 a slot 28 is provided, and a pin 29, extendedout from the mandrel, is adapted to operate in this slot and preventsthe pin 26 from being thrown out of the way when the spring 27 forcesthe rod 18 up, the operating-pin 26 having passed out from the casing.

The mandrel 2- may be connected to the sub in the ordinary or anypreferred man-' ner.

It is seen that by making the transverse slots of greater width than thedownward or vertical slots abutments 5 are provided upon which theshoulders 12 of the bits contact or bear. The pins 8 are thus relievedfrom the strain of the weight of the bits when the underreamer is beinglowered into the casing or pulled up out therefrom.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. In an underreamer, in combination, a hollow mandrelhaving a slotted portion at its lower end, reaming-bits pivoted to saidmandrel within said slotted portion, said bits provided with shouldersadapted, when in expanded position, to abut against the end of saidslotted portion and extending through said slotted portion and expandinglaterally therethrough, automatic means carried within said mandrel andadapted to normally hold said bits in expanded position, and meansadapted to contact with the casing and automatically disengage saidexpanding means and permit said bits to contract.

2. In an underreamer, in combination, a hollow mandrel, the lower endhaving a downwardly and transversely slotted portion, said transverseslot being of greater width than the downward or vertical slot,reaming-bits pivoted to said mandrel and extending through said slots,said reaming-bits provided with shoulders adapted to contact with theabutments or shoulders formed by the walls of said slots, said bitsprovided with shoulders adapted, when said bits are expanded, to abutagainst the slot-ted end of said portion, automatic means carried withinsaid mandrel adapted to normally hold said bits in expanded position,and means adapted to contact with the casing and automatically disengagesaid expanding means and permit said bits to contract.

3. An underreamer, comprising in combi' nation, a mandrel provided witha central bore and having a transversely-slotted lower portion, having avertical slot of less width communicating from its lower end into saidtransverse slot, whereby shoulders are provided by the walls of saidslot, reaming-bits pivoted to said mandrel within said transverse slot,said reaming-bits provided with portions adapted to bear upon saidshoulders and with shoulders adapted, when said bits are expanded, to

abut against the end of said mandrel, and means for expanding andcontractingsaid bits.

4. An underreamer, comprising in combination, a mandrel provided with acentral bore and having a transversely-s1otted lower portion having avertical slot extending inward from the end and communicating into saidtransverse slot, reaming-bits pivotally mounted on said mandrel withinsaid transverse slot and provided with shoulders adapted when inposition for underreaming to abut against the end of the mandrel, andmeans for expanding and contracting the bits.

5. An underreamer, comprising in combination, a mandrel provided with acentral bore, reaming-bits pivotally mounted in the lower end of saidmandrel, a rod slidably mounted in said central bore and provided withmeans for expanding said bits, said rod provided with a head or nut atits upper end, a barrel or cylinder about said rod and fixed in saidcentral bore, a spring interposed about said rod and bearing against thetop of said barrel and against said head or nut, and means extendingthrough said mandrel and operating within said barrel below the topthereof and adapted to operate against said rod and adapted upon contactwith the casing to force said rod against the tension of said spring topermit said bits to contract.

6. An underreamer, comprising in combination, a mandrel provided with acentral bore, reaming-bits pivotally mounted in the lower end of saidmandrel, a rod slidably mounted in said central bore and provided withmeans for expanding said bits and with a head or nut on its upper end, abarrel or cylinder about said rod and fixed in said central bore, saidbarrel provided with a longitudinal slot, a spring interposed about saidrod and bearing upon the top of said barrel and against said head or nuton said rod, said mandrel provided with an inclined way communicatinginto said central bore, and an operating-pin mounted in said way andoperating upon said rod and adapted to contact with the casing to forcesaid rod against the tension of said spring and permit the bits tocontract.

7 An underreamer, comprising in combination, a mandrel provided with acentral bore, reaming-bits pivotally mounted in the lower end of saidmandrel, a rod slidably mounted in said central bore and provided withmeans for expanding said bits and with a head or nut on its upper end, abarrel or cylinder about said rod and fixed in said central bore, saidbarrel provided with a longitudinal slot, a spring interposed about saidrod and hearing upon the top of said barrel and against a head or nut onsaid rod, said mandrel provided with an inclined way or perforation, anoperating-pin mounted in said way and hearing against a portion of saidrod and adapted to contact with the casing to force said rod against thetension of said spring to permit the hits to contract, and means forpreventing the tension of said spring throwing said operating-pin outfrom said way when said bits are expanded.

8. An underreamer, comprising in combination, a mandrel provided with acentral bore,

' reaming-bits pivotally mounted in the lower end of said mandrel, a rodslidably mounted in said central bore and provided with means forspreading said bits and with a head or nut on its upper end, a barrel orcylinder sur-' rounding a portion of said rod, said rod provided with aflange or shoulder within said barrel, 'said barrel provided with alongitudinal slot, said flange or shoulder projecting into said slot, aspring interposed about said rod above said barrel and bearing upon theupper end or head thereof and operating against said head or nut uponsaid rod, said mandrel provided with a perforation or way, anoperating-pin in said way or perforation adapted to bear against saidflange or shoulder and to contact with the casing to force said rodagainst the tension of said spring to permit the bits to contract, andmeans for preventing said spring throwing said operating-pin out fromsaid perforation or way when the bits are expanded.

In witness whereof I have hereunto set my hand, this 29th day of April,A. D. 1903, in Los Angeles, in the county of Los Angeles and State ofCalifornia.

' ARTHUR WVILLARD.

